Integrated allyl isothiocyanate effectively reduces anthracnose and maintains the marketing quality of chitosan-polystyrene sulfonate multicoated mango

Ripe 'Nam Dok Mai' mango (Mangifera indica L.) is an economic important fruit of Thailand.
Anthracnose and rapid decay are the main marketing obstacles. Our previous study revealed that
multicoating between chitosan (CTS) and polystyrene sulfonate (PSS) delayed mango fruit ripening
but was ineffective for disease reduction. This study aimed to investigate allyl isothiocyanate (AIT),
a natural antifungal compound integrated with multilayer coating at a multilayer coating of 0.5%
CTS and 0.5% PSS to maintain the quality of coated mango. In vitro activity of AIT at 0%, 0.05%,
0.1%, 0.15% and 0.2% (v/v) against Colletotrichum gloeosporioides were evaluated using poisoned
food technique. The concentrations above 0.15% AIT effectively inhibit the mycelial growth.
Subsequently, mango fruits were coated with multicoating treatments (uncoated, 0.15% AITtreated,
3½ layers of 0.5% CTS/0.5% PSS coated, and 3½ layers of 0.5% CTS/0.5% PSS+0.15%
AIT coated fruits) and stored at a retail condition of 25+3oC, 60-75% RH. Compared with uncoated
fruit, the multicoated fruit were delayed in the fruit respiration and ethylene production rates up to
29.55% and 48.94%, respectively. The multicoating delayed changes in weight loss, firmness, and
antioxidant capacities. Furthermore, with the AIT function of fungal growth inhibition, 0.5%
CTS/0.5% PSS+0.15% AIT mangoes intensely reduced the severity of the anthracnose disease in
normal and inoculated fruits.